The money will be used to construct a new paint shop, expand the existing body shop and other new technology designed to boost productivity.

"Truck customers demand top quality," Cathy Clegg, GM vice president for North America Manufacturing, said in a statement. "The upgrades at Ft. Wayne Assembly will enable our team to continue delivering for them for years to come."

Work will start in June and take several years to finish, the company said.

The improvements will enable a better paint finish and more customized paint options. The investment also includes new skillet conveyor systems to ease the job of installing the instrument panel.

The plant has assembled full-size pickup trucks since it opened in 1986. Today, with sales of Silverado and Sierra running near their highest levels in the last 10 years, Ft. Wayne's 3,800 workers are working across three shifts, including many Saturdays, to keep up with demand.

GM did not say whether it will hire additional workers in Ft. Wayne, but the investment will enable it to retain the current employment level as long as trucks sales remain strong.

"These new technologies and equipment will help fulfill the mission of the men and women of Ft. Wayne assembly and UAW Local 2209 to build the best full-size trucks available," UAW Vice President Cindy Estrada said in a statement. "The investment improves the plant's competitiveness so we can continue contributing to the community as well."

GM is investing $5.4 billion to upgrade 40 factories in the U.S. and $2.4 billion of that is targeted at two assembly plants, Ft. Wayne and Arlington, Texas, where it makes the Chevrolet Tahoe, Suburban, GMC Yukon and Cadillac Escalade.